What do you think became of Daniel's first wife, mother of Niall and Phoebe?

There was no real mention of Daniel's first wife after she took the kids away from Daniel. Even after Phoebe's murder, she really wasn't brought up. Why do you think?

She must have been a very vindictive person to have completely shut Niall and Phoebe out of Daniel's life. I cannot imagine anyone preventing a child's letters, etc. from their father from reaching them.

I do not know enough about her to have an opinion

I do not know enough about her to have an opinion

She was such a minor part of the whole story that Maggie O'Farrell's expanding on her character further than just the fact she was evil would have detracted from the plot of the book. There seemed to be enough characters to keep the reader busy! Some mystery with an individual is often more enticing than not.

She is never really a developed character, nor was that necessary, in my opinion. What we know about her is that she was unfaithful herself, but couldn't handle that conduct from Daniel, and that she assuaged her pride by refusing to honor his right to a relationship with his children, and actively worked to keep them from knowing of his efforts. "Parental alienation" is now a legal term, and it applies here. While some acrimony in divorce is normal, parental alienation is not, and the extreme version she demonstrated is very rare, so we can assume that she was a disturbed, controlling person, someone with a serious narcissistic personality disorder, and not likely to have developed solid relationships with her own children as they grew beyond the reach of her control. My reaction as a reader is that I don't much care what happens to a person like that.